The present invention relates generally to a Computed Tomography (CT) system and specifically to a stationary CT system with a compact x ray source assembly.
Computed tomography (CT) is a technique which creates two-dimensional cross-sectional images from three-dimensional body structures. The CT imaging system primarily includes a CT gantry and a patient table or a couch. The gantry is a moveable frame that contains a x-ray source which is typically a x ray tube including collimators and filters, detectors, data acquisition system (DAS), rotational components including slip ring systems and all associated electronics such as gantry angulation motors and positioning laser lights.
In known third generation CT systems (spiral/helical), the x ray source and the detector array are rotated with a gantry within the imaging plane and around the object to be imaged so that the angle at which the x ray beam intersects the object constantly changes. X ray sources typically include x ray tubes, which emit the x ray beam at a focal spot. An x ray detector is a crystal or ionizing gas that when struck by an x-ray photon produces light or electrical energy. The two types of detectors utilized in CT systems are scintillation or solid state and xenon gas detectors. The CT systems may typically include post patient collimators for reducing scattered radiation at the detector.
Current third generation CT systems involve rotating an x ray source around the patient to do body scans and have limitations regarding scanning speeds.
Next generation CT architectures, which include stationary CT concept, offer high scan speeds and they involve directing high power, fast moving electron beams onto stationary x ray targets to produce x rays. The Stationary CT concept presents unique challenges in the target and geometric design of the compact x ray producing apparatus in CT scan systems. There are significant thermal and structural risks associated with the impact of focused, high power electron beam on the stationary x ray target and the resulting heat distribution on the various components of the stationary CT systems.
It is therefore desirable to provide compact CT system geometries that mitigate the thermal and structural risks and can house the principal CT system components including the stationary target, electron beam source, focusing chamber and radiation window, and also meet high power and faster scans requirements of advanced CT systems.